Siren



May 19, 1936. c 2,041,431

- SIREN Filed July 18, 1935 1 2 Sheets-Shegt l INVENTOR, i Harry BY g R ATTOzzEY.

I 19, 1936. cc 2,041,431

' SIREN v Filed July 18, 1955 2 Sheets-Sheet 2 INVENTOR,

Envy Kiwi, BY

Patented May 19, 1936 UNITED STATES PATENT OFFICE SIREN Harry Ricci, Stapleton, N. Y.

Application July 18, 1935, Serial No. 31,958

12 Claims.

My present invention relates generally to signaling devices, and has particular reference to sirens of the character which are used on police cars or the like.

It is a general object of the invention to provide an improved siren of the general type which is illustrated in my earlier Patent Number 1,956,105, issued April 24, 1934.

The present type of siren consists essentially of a stator and a complementary rotor, these parts being provided with peripheral apertures of a predetermined character which cause a characteristic sound to be produced when the rotor rotates with relative rapidity with respect to the stator.

The present siren is of the type in which no pivotable movement of the siren as a Whole is required to effect operation, and in which the stator may be rigidly and permanently as- The operation stantly rotating driving shaft which is permanently associated, in driving relationship, with the ordinary conventional fan belt of the motor.

It is one of the more particular objects of the present invention to provide a siren construction by means of which an almost instantaneous sound may be produced, when desired, and where'- by the cessation of the sound may be caused to p be equally instantaneous, or more gradual, de-

pending upon the particular purposes for which the siren is intended.

A further particular object of the present invention is to provide a construction which is of greater simplicity, of enhanced staunchness and reliability, and involving a minimum number of normally rotating parts.

The present improved siren is not only light in Weight, relatively inexpensive to manufacture and install, extremely compact both in structural nature and in mode of operation, but is of a character whereby it may be efficiently associated with motor vehicles of the present day type, especially those in which the vehicle manufacturer has arranged the hood of the motor in relatively close relationship to the motor and associated parts within the hood. In this respect, the present improved siren is similar to that illustrated in my earlier patent, the installation and operation requiring no replacement of the conventional fan or fan belt of the motor.

In brief, a siren of the present improved character is simpler in nature, less expensive to manufacture, easier to install, and more efficiently controllable than sirens of conventional character and comparable capacity.

I achieve the foregoing objects, and such other objects as may hereinafter appear or be pointed out, in the manner illustratively exemplified in the accompanying drawings, wherein Figure l is a perspective view of a siren of the present type shown in association with a typical modern automotive vehicle motor;

Figure 2 is an enlarged longitudinal cross-sec tional view through the present type of siren;

Figure 3 is a fragmentary view of a portion of Figure 2, taken substantially along the line 3'3 of Figure 2;

Figure 4 is an exploded view showing the essential elements of the present construction;

Figure 5 is a View similar to Figure 2, showing the parts in the relationship they assume when a siren sound is being produced; and

Figure 6 is a cross-sectional view taken substantially along the line 6--% of Figure 5.

In Figure 1, I have shown a typical motor I of the type which is found in modern automobiles. At the forward end of the crank shaft I have shown the usual pulley II which is permanently connected, by means of the fan belt l2, with the fan l3 for the purpose of driving the latter. I have also shown this belt arranged around a pillley M for operating the generator.

In the type of motor illustrated, the motor housing includes a substantially circular portion l which encloses the timing gear and shaft, and it is convenient to mount the present siren to this portion of the housing so as to position the sir-en proper substantially above this portion. The present siren is provided with a driving shaft which will be presently described, on the end of which a pulley I6 is mounted; and it is a relatively simple matter either to stretch the fan belt I2 over this pulley or to substitute a slightly longer fan belt for the one which is furnished by the manufacturer of the vehicle. In any event, the present siren, when completely installed in a motor of the type shown, assumes the relationship of Figure 1; and it is to be observed that it is securely attached to the motor housing in an unpivotable and immovable manner, with the fan belt l2 permanently engaging around the pulley I6 so that the driving shaft of the siren is caused to rotate continuously whenever the motor l0 operates.

The stator of the present construction consists of the substantially circular end wall I! and the similar opposed end wall l8, the peripheral wall I9 being provided with spaced openings 20 which contribute to the production of the characteristic sound. The end wall I? has a relatively large medial opening 21 through which the air enters when the siren operates. Because of this, this wall is generally termed the front wall of the siren even though, when the siren is installed, this wall may face the rear of the vehicle.

The rear wall I8 is preferably formed integrally with the peripheral wall [9 and is provided with the extended bearing portion 22. The two walls I! and I8 form parts of two separate castings or elements, as shown most clearly in Figure 4,

which are secured together in permanent relationship by any suitable means (not shown).

The front wall I! is also provided with an axial bearing portion 23, supported by the spokes or spider elements 24.

In accordance with my invention, the driving shaft 25, which carries the pulley I6 hereinbefore referred to, is journaled in the bearing 22, and anti-friction bearings 26 are interposed between the shaft and the bearing 22.

The shaft 25 is unusually short in the present construction, and does not extend into the body of the stator. Just inside the rear wall l8 the shaft terminates and has rigidly secured to it a clutch disc 21. As will be obvious from the description given, the pulley [6, the shaft 25, and the disc 2'! are constantly rotating when the motor 10 is operating.

Mounted in the bearing 23 is a shaft or spindle 28 which is aligned with the shaft 25. While the term spindle is used herein and in the claims to designate the element 28, it should be noted that this element is mounted in a manner which permits a certain limited axial movement thereof relative to the wall H, but which prevents any rotation. This may be accomplished, for example, by means of a longitudinal keyway 29 cooperating with a suitable key or pin secured to the bearing 23.

Mounted on the inner end of the spindle 28, for free rotation relative thereto, is the rotor 30. Anti-friction bearings 31 are interposed between the hub of the rotor and the reduced portion 32 of the spindle 28. On the inner face of the rotor a complementary clutch disc 33 is mounted, and it is rigidly secured to the rotor hub by any suitable means, for example, by means of pins or studs 34. The peripheral portion of the rotor is of conventional character, being provided with vanes 35 and peripheral openings 36 which contribute toward the production of the characteristic sound when the rotor rotates.

At its outer end the spindle 28 carries an enlargement 31, and a compression spring 38 is interposed between the enlargement 31 and the outer end of the bearing 23. A control lever 39, pivoted to the stator at 48, has its free end 4| engaged over the enlargement 31 so that when the opposite end of the lever is pulled in the direction of the arrow 42, by means of a control cable 43 or the like, the spindle 28 is urged toward the shaft 25 against the continuous urgence of the compression spring 38.

Before describing the operation of the device, I draw attention to the braking discs or shoes 44 which are secured to the inner surface of the front wall I1 by any suitable means, such as the studs 45. These shoes or inserts are arranged at suitably spaced intervals and are positioned to be encountered by the front wall 46 of the rotor.

The distance between the walls I! and I8 of the stator is slightly greater than the thickness of the rotor. Accordingly, a certain limited axial shifting of the spindle 28 is possible, the movement toward the shaft 25 being limited when the clutch disc 33 engages with the clutch disc 21; and the movement in the opposite direction being limited either by the engagement of the wall 46 with the brake discs 44, or by the abutment of the lever 39 against the adjustable control screw or stop 41.

Assuming that the device is to be adjusted for almost instantaneous cessation of sound, the adjustable screw 41 is manipulated so that the spring 38 may push the spindle 28 sufliciently far to effect an abutment of the wall 46 with the brake discs 44. With this adjustment made, the normal position of the parts is shown in Figure 2. The rotor is held toward the wall I! by means of the spring 38, and the only rotating elements are the pulleys IS, the shaft 25, and the clutch 27. When a .siren sound is desired, the cable 43 is pulled (preferably from a convenient point at the dashboard of the vehicle), and this pushes the spindle 28 toward the shaft 25, thereby pressing the clutch discs 33 and 21 into engagement. The constant rotation of the disc 27 imparts an almost instantaneous corresponding rotation to the rotor, and the characteristic siren sound is thus produced. When the cable 43 is released, the spring 38 pushes the spindle back to its normal position, thereby not only withdrawing the clutch discs from mutual engagement, but also automatically bringing the rotor into braking relation to the discs 44. The cessation of rotation may thus be practically instantaneous, if desired. This is a highly desirable advantage of the present construction because, when sirens of the present type are used on police cars or the like, it is often necessary, as the car approaches the scene of a 2 hold-up, to silence the siren instantaneously.

If it is desired to use the siren under circumstances which do not require an instantaneous cessation of sound, it is a relatively simple matter to adjust the abutment screw 41 so that the out of engagement, but no braking action takes place. Accordingly, the rotor is permitted to continue its rotation through its inherent inertia, and the characteristic sound will diminish gradually as the rotor gradually stops rotating.

Similarly, adjustments of the abutment 41 can be made whereby a mild braking action is effected automatically, so that the siren sound, while not diminishing instantaneously, may nevertheless be caused to cease in a more rapid manner than would otherwise be the case. In fact, any de- 45 sired speed of cessation of rotation of the rotor may be provided for.

It will be noted that the amount of movement of the rotor from the inoperative position of Figure 2 into the operative position of Figure 5, and

back again, is extremely slight. Accordingly, there is a minimum likelihood of wear and tear, and the mode of operation is thus rendered as efficient as the entire siren construction itself. No additional space is required for moving parts or for the adjustment of parts during initiation and discontinuance of siren operation. The entire siren, when once installed, remains stationary, and may thus be fitted with ease into the small available space which is afforded therefor by modern motor vehicle construction. The siren is secured to the motor housing in any convenient manner, the reference numeral 48 being intended to designate a bracket which is suitable for this purpose. This mounting is preferably of the character illustrated more clearly in my earlier patent.

It will be understood that changes in the details, herein described and illustrated for the purpose of explaining the nature of my invention, may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims.

It is, therefore, intended that these details be interpreted as illustrative, and not in a limiting sense.

Having thus described my invention, and illustrated its use, what I claim as new and desire to secure by Letters Patent is- 1. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, and means for axially shifting the rotor into and out of a position in which said clutch discs are in engagement.

2. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, yieldable means for normally retaining the rotor in a position in which the clutch discs are disengaged, and means for axially shifting the rotor into a position in which said clutch discs are engaged.

3. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, means for axially shifting the rotor into and out of a position in which said clutch discs are in engagement, and means automatically braking the rotor when it is shifted out of said position.

4. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, means for axially shifting the rotor into and out of a position in which said clutch discs are in engagement, and a brake shoe secured to the stator and positioned to be encountered by the rotor when the latter is shifted out of said position.

5. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, yieldable means for normally retaining the rotor in a position in which the clutch discs are disengaged, means for axially shifting the rotor into a position in which said clutch discs are engaged, and means automatically braking the rotor when it is shifted into said first-mentioned position.

6. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, yieldable means for normally retaining the rotor in a position in which the clutch discs are disengaged, means for axially shifting the rotor into a position in which said clutch discs are engaged, and means automatically braking the rotor when it is shifted into said first-mentioned position, said means comprising a brake shoe secured to the stator and positioned to be encountered by the rotor when the latter is shifted into said first-mentioned position.

'7. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, means for axially shifting the rotor into and out of a position in which said clutch discs are in engagement, a brake shoe positioned to brake the rotor when the latter is shifted out of said position, and adjustable means to limit the shifting movement of the rotor and thereby alter the effectiveness of said brake shoe.

8. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, means for axially shifting the rotor into and out of a position in which said clutch discs are in engagement, a brake shoe secured to the stator and positioned to be encountered by the rotor when'the latter is shifted out of said position, and adjustable means to limit the extent of movement of the rotor toward said brake shoe.

9. In a siren, a stator, a driving shaft axially journaled in said stator, a clutch disc secured to said shaft, a rotor axially journaled in the stator independent of said shaft, a complementary clutch disc secured to said rotor, yieldable means for normally retaining the rotor in a position in which the clutch discs are disengaged, means for axially shifting the rotor into a position in which said clutch discs are engaged, a brake shoe secured to the stator and positioned to be encountered by the rotor when the latter is shifted into said first-mentioned position, and adjustable means to limit the extent of movement of the rotor toward said brake shoe.

10. In a siren, a stator having opposed end walls, a driving shaft axially journaled in one end wall, a clutch disc on the inner end of said shaft, a spindle axially mounted in the opposite end wall, a rotor mounted for free rotation upon said spindle but secured to the latter for axial movement therewith, a complementary clutch disc secured to said rotor, and means for axially shifting said spindle to bring the rotor into and out of a position in which said clutch discs are in engagement.

11. In a siren, a stator having opposed end walls, a driving shaft axially journaled in one end wall, a clutch disc on the inner end of said shaft, a spindle axially mounted in the opposite end wall, a rotor mounted for free rotation upon said spindle but secured to the latter for axial movement therewith, a complementary clutch disc secured to said rotor, and means for axially shifting said spindle to bring the rotor into and out of a position in which said clutch discs are in engagement, said means comprising a spring normally urging the spindle away from said driving shaft, and a control lever adapted to bear against said spindle against the action of said spring.

12. In a siren, a stator having opposed. end walls, a driving shaft axially journaled in one end wall, a clutch disc on the inner end of said shaft, 2. spindle axially mounted in the opposite end wall, means permitting axial movement of the spindle but looking the same against rotation relative to the stator wall in which it is mounted, a rotor mounted for free rotation upon said spindle but secured to the latter for axial movement therewith, a complementary clutch disc secured to said rotor, and means for axially shifting said spindle to bring the rotor into and out of a position in which said clutch discs are in engagement.

HARRY RICCI. 

